For 2015, we teamed up with ATI to develop a tactical chassis for our semi-automatic rimfire platform, the 512. Chambered in .22 LR or .22 WMR, it comes with a 16.5″ barrel, 1/2×28 muzzle threads, top Picatinny rail, 6-position stock and higher magazine capacity than the standard gun. One of the best features of the 512 platform is that it uses the same reliable single-stack mags as the 455.